Profile carriers having a base profile of metal constructed as a hollow profile and having reinforcement layers of fiber/plastic compounds serve, for example, as extension arms of construction machines, such as cranes. The metal base profile has a polygonal closed cross-section. Mutually facing wall portions of the profile wall of the base profile are provided in each case with a reinforcement layer at the inner side thereof. In order to produce the connection between the reinforcement layers and the profile wall of the base profile, which connection provides the reinforcement effect of the reinforcement layers, the reinforcement layers are adhesively bonded to the associated wall portion of the profile wall via their plastic material portion. In order to improve the adhesive bonding of the reinforcement layers to the profile wall, the respective wall portions of the profile wall are pre-treated (e.g., degreased and sand-blasted) before the fiber/plastic material compounds forming the reinforcement layers is applied.